Important Terminology

We recommend that, before proceeding, you familiarize yourself with the following terminology:

Upgrade—To update BEA WebLogic Server from a previous release or service pack to a more recent one. This process may include updating an existing application or domain configuration to run in a more recent version of WebLogic Server.

Migrate—To move an application or domain configuration from a third-party product to a BEA product.

Interoperability—(1) The ability of an application deployed in one release or service pack to communicate with another application that is deployed in a different release or service pack. (2) The ability of WebLogic Server components to communicate with third-party software via standard protocols.

Compatibility—The capability of an application built using one release or service pack to run in another release or service pack, regardless of whether the application was rebuilt.

Overview of the Upgrade Process

The process required to upgrade an application environment depends on the scope of the application. An application environment includes a WebLogic domain and any applications and application data associated with the domain. It may also include external resources, such as firewalls, load balancers, and LDAP servers.

Includes the Administration Server (AS) and optionally one or more Managed Servers (for example, MS1, MS2, MS3, and MS4). The servers in a domain may span multiple machines. Furthermore, you can group Managed Servers into clusters to support load balancing and failover protection for critical applications. For more information about WebLogic domains, see "Understanding WebLogic Server Domains" in Understanding Domain Configuration at http://download.oracle.com/docs/cd/E13222_01/wls/docs90/domain_config/understand_domains.html.

Any J2EE applications, including Web applications, EJBs, and so on. Typically, applications are deployed to one or more Managed Servers in a domain. Depending on the deployment strategy, applications may reside locally on a machine or be accessible via a shared directory. In addition, external client applications may access the application environment from outside a firewall.

Software components, such as databases for storing domain and application data, load balancers, and firewalls.

Verify that all external resources are compatible with WebLogic Server 9.0.

Each step in the upgrade process is described in more detail in this document.

How the Upgrade Wizard Simplifies the Upgrade Process

The WebLogic Upgrade Wizard guides you through the steps required to upgrade a WebLogic domain that is compatible with WebLogic Server 6.1, 7.0, or 8.1 such that it runs in a WebLogic Server 9.0 application environment. As part of the upgrade process, you must upgrade any custom security providers and Node Managers used in the domain.

You can step through the upgrade process interactively, using the graphical user interface (GUI), or "silently," by creating an upgrade script and running it.

Interoperability and Compatibility with Previous Releases

Application environments that run with WebLogic Server 9.0 can interoperatre with application environments built on WebLogic Server 7.0 or 8.1.

Most existing WebLogic Server applications can be run without modification in the new WebLogic Server 9.0 application environment. You should review the compatibility information described in Compatibility with Previous Releases to determine whether any feature changes affect the applications in your environment. If your application uses APIs that have been deprecated or removed, then you may encounter warnings or exceptions at run time.